1. Field of the Invention
The present invention relates to a bolt, rivet or similar fastener for fastening various kinds of work, e.g., aggregates and panels constituting a machine or a structure as well as machine parts. More particularly, the present invention is concerned with a fastener which allows a minimum of stress concentration to occur therein when subjected to a shearing force ascribable to an axial force or a bending force acting on the work.
2. Description of Background Art
Fasteners including bolts and rivets are a traditional implement for connecting aggregates, panels, machine parts and so forth. The problem with a conventional fastener of this kind is that when subjected to an impact force due to the vibration of a machine, the passage of an automobile, an earthquake or similar occurrence, the fastener cannot receive the force evenly and, therefore, causes a shearing Force to act thereon. The shearing force often invites stress concentration great enough to break the Fastener. This is ascribable to, for example, the irregular pitch of a bolt, the inaccurate verticality of a hole for receiving the bolt, and the diameter of the hole which is greater than that of the bolt.